Table 1 Demografic data: Age, weight, height, BMI and lowest oxygen saturation during induction and one lung ventilation represented as median and interquartile range; * p = < 0.05; Basic airway characteristics are presented as total number and percent

Sex

male: 224

female: 119

male: 57

female: 43

Age (years)

64.0 [55.0–74.0]

60.0 [53.0-69.5] *

Height (cm)

172.0 [164.0-180.0]

174.0 [165.5–182.0]

Weight (kg)

77.0 [64.0–88.0]

78.0 [68.5–90.0]

Body mass index

25.8 [22.4–29.1]

25.65 [22.35–29.35]

ASA score

I: 11 (3.2%)

II: 144 (42%)

III: 178 (51.9%)

IV: 10 (2.9%)

V: 0 (0%)

I: 5 (5%)

II: 36 (36%)

III: 53 (53%)

IV: 6 (6%)

V: 0 (0%)

Mallampati score

I: 43 (12.5%)

II: 92 (26.8%)

III: 22 (6.4%)

IV: 2 (0.6%)

Not specified: 184 (53,6%)

I: 12 (12%)

II: 24 (24%)

III: 8 (8%)

IV: 0 (0%)

Not specified: 56 (56%)

Cormack/Lehane score

I: 236 (68.8%)

II: 59 (17.2%)

III: 9 (2.6%)

IV: 1 (0.3%)

Not specified: 38 (11.1%)

I: 83 (83%)

II: 13 (13%)

III: 1 (1%)

IV: 0 (0%)

Not specified: 3 (3%)

DLT size

35 Ch: 42 (12.2%)

37 Ch:129 (37.6%)

39: Ch:172 (50.1%)

35 Ch: 7 (7%)

37 Ch:48 (48%)

39: Ch:45 (45%)

lowest oxygen saturation during induction

99.0 [98.0–100.0]

99.0 [98.0–100.0]

lowest oxygen saturation during one lung ventilation

96.0 [94.0–98.0]

96.0 [93.0–98.0]